CN112794737A - Process for preparing potassium calcium magnesium nitrate and potassium magnesium ammonium nitrate from medium-low grade phosphate ore - Google Patents
Process for preparing potassium calcium magnesium nitrate and potassium magnesium ammonium nitrate from medium-low grade phosphate ore Download PDFInfo
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Abstract
The invention discloses a process for preparing potassium calcium magnesium nitrate and potassium magnesium nitrate from medium-low grade phosphate ore, which comprises the following steps: concentration: taking middle-low grade phosphorite as raw material, preparing P by the working procedures of crushing, calcining, digesting, leaching, filter pressing separation and the like2O5The low-magnesium phosphate concentrate with the weight percentage of more than or equal to 34.5 percent and the weight percentage of MgO less than or equal to 0.85 percent is collected and concentrated in the leaching solution in the filter pressing step, and the calcium magnesium nitrate concentrated solution with the weight percentage of more than 25 percent is obtained; decalcification: concentrating calcium magnesium nitratePumping the mixture to a decalcification reaction tank, reacting the mixture with a potassium sulfate solution, adding an alkaline substance for neutralization, and filtering and separating to obtain a decalcification solution and a calcium sulfate filter cake; and (3) granulation: and (3) feeding the decalcification solution into a preheater and a heat exchanger, then treating by adopting a forced circulation type evaporator, separating evaporated materials, feeding into a granulation feeding groove, feeding into a granulator for granulation, and wrapping to obtain potassium magnesium nitrate and potassium calcium magnesium nitrate products. Downstream product that this application obtained can both reuse, but realizes the cyclic utilization and the green emission of resource, obtains better economic benefits simultaneously.
Description
Technical Field
The invention relates to the technical field of inorganic chemical industry, in particular to a process for preparing potassium calcium magnesium nitrate and potassium magnesium nitrate from medium-low grade phosphate ore.
Background
China's storage of phosphate ore is second in the world, but compared with the world, the storage of phosphate ore has larger difference in the aspects of ore quality, selectivity, phosphate ore mining and the like, the basic storage of the phosphate ore which can be processed and utilized is relatively lower, only 40.54 hundred million tons, and a lot of low-grade ores and P of the low-grade ores2O5The mass fraction of rich ore is more than 30 percent and is only 11.08 hundred million tons, and the Chinese phosphorite P2O5The average mass fraction is about 17 percent, most of phosphate ores can meet the production requirements of phosphoric acid and high-concentration phosphate fertilizers after being enriched, and according to the current speed of exploiting phosphate ores, if the rich ores with the mass fraction of 30 percent can be maintained for about 10 years, the economic reserves can be maintained for about 40 years, and the middle and low-grade phosphate ores with higher cost are forced to be exploited in the future.
At present, the mineral separation process of the medium-low grade phosphorite basically adopts physical mineral separation. The detection of the phosphorite in the Van cattle farm confirms that the magnesium element which is the main impurity in the phosphorite is embedded in the phosphorite in the form of dolomite, and through crushing and grinding the phosphorite, under the action of a proper flotation agent, dolomite in partial phosphorite can be floated and discharged (namely, a reverse flotation process), so that phosphate concentrate is obtained. Limited by technical and economic indexes, and the grade P of the phosphate concentrate obtained by reverse flotation2O530% -34% and MgO 0.8-1.5%, and obtaining higher grade phosphate concentrate means the reduction of the yield of phosphorus and the increase of cost. In general, the grade P is selected2O5Adopting 20-28% calcium (magnesium) phosphate ore onceThe recovery rate of phosphorus in reverse flotation or secondary reverse flotation is between 90 and 96 percent, and the beneficiation cost is between 60 and 150 yuan/ton (32 percent P2O5Phosphate concentrate meter); after mineral separation, 0.3-0.7 ton of tailings are discharged, wherein P is contained in the tailings discharged by primary reverse flotation2O5Less than or equal to 12 percent, and MgO more than or equal to 10 percent; the P content in the tailings discharged by secondary reverse flotation2O5Less than or equal to 10 percent, MgO more than or equal to 15 percent; the magnesium content of the phosphate concentrate obtained by reverse flotation can be reduced to 0.8-1.5%, the requirement of phosphate rock for wet processing under most conditions can be met, but the magnesium content is still too high for producing water soluble fertilizer, polyphosphoric acid, ammonium polyphosphate and other varieties and a high tower melt granulation process.
The method for separating calcium and magnesium in the middle and low grade phosphate ore in the prior art comprises the following steps: calcining and digesting middle-low grade phosphorite, adding ammonium nitrate to leach, filtering, concentrating and granulating leaching solution to prepare calcium ammonium nitrate, adding ammonium sulfate to leach leaching residues, filtering, drying filter residues to prepare phosphate concentrate, concentrating and granulating filtrate to prepare magnesium ammonium sulfate.
Disclosure of Invention
Aiming at the defects in the technology, the invention provides the process for preparing potassium calcium magnesium nitrate and potassium magnesium ammonium nitrate from the medium-low grade phosphate ore, so that the obtained downstream products can be repeatedly utilized, the resource recycling and green emission are realized, and the better economic benefit is obtained.
The invention discloses a process for preparing potassium calcium magnesium nitrate and potassium magnesium nitrate from medium-low grade phosphate ore, which comprises the following steps:
concentration: the quality fraction P is prepared by taking middle-low grade phosphorite as a raw material through the working procedures of crushing, calcining, digesting, leaching, filter pressing separation and the like2O5The low-magnesium phosphate concentrate with the weight percentage of more than or equal to 34.5 percent and the weight percentage of MgO less than or equal to 0.85 percent is collected and concentrated in the leaching solution in the filter pressing step, and the calcium magnesium nitrate concentrated solution with the weight percentage of more than 25 percent is obtained;
decalcification: pumping the calcium magnesium nitrate concentrated solution into a decalcification reaction tank, reacting with a potassium sulfate solution from a dissolving tank, adding an alkaline substance for neutralization, and filtering and separating to obtain a decalcification solution and a calcium sulfate filter cake;
and (3) granulation: and (3) feeding the decalcification solution into a preheater and a heat exchanger, then treating by adopting a forced circulation type evaporator, separating the evaporated material by a flash separator, feeding the separated material into a granulation feeding tank, feeding the granulation feeding tank to a granulator for granulation, cooling, screening and wrapping to obtain potassium magnesium nitrate and potassium calcium magnesium nitrate products.
Preferably, in the concentration step, the crushing comprises crushing the medium-low grade phosphate ore to a particle size of not more than 4.5 mm; the calcining temperature is controlled at 900-1100 ℃, and the time is controlled at 1.5-4 h; the leaching temperature is 75-90 ℃, the reaction time is 1.5-5h, and the reaction pH is controlled between 4.0-6.5.
Preferably, decalcification is carried out by using a potassium sulfate solution; the reaction temperature of the decalcification is controlled to be 20-110 ℃, and the reaction time is 3-6 h; neutralizing with one of calcium hydroxide and ammonia water to obtain a reaction pH of 6.5-7.5.
Preferably, the slurry after decalcification is subjected to first solid-liquid separation to obtain a decalcification solution and a filter cake, and the filter cake is washed and dried to obtain a calcium sulfate product for construction.
Preferably, the filter cake is washed for the first time, a first filter cake and a first filtrate are obtained through separation, and the obtained first filtrate is collected and used for dissolving potassium sulfate placed in the dissolving tank; and adding water into the first filter cake for secondary washing, and then separating to obtain a second filtrate and a second filter cake, wherein the second filtrate is used as a first washing liquid of the next batch of filter cakes, and the second filter cake is dried and then used as a calcium sulfate product for buildings.
Preferably, the decalcification liquid is pumped into a preheater, condensate generated by medium-pressure steam is used as a heating medium, the preheated decalcification liquid enters a heat exchanger and then enters a forced circulation type evaporator, the temperature is controlled at 160-.
Preferably, after the concentrated solution separated by the flash separator exchanges heat with the feed liquid to be evaporated, the temperature is controlled to be 135-155 ℃, and then the concentrated solution enters a granulation feeding trough; the condensate produced by the concentration system is used for the second washing water of the first filter cake.
Preferably, the concentrated solution exchanges heat with the feed liquid to be evaporated through a heat exchanger and then is sent to a melting tank, auxiliary materials such as boron, zinc and the like are metered and then sent to the melting tank, and after the temperature is reduced to 130-.
Preferably, the granulation section is followed by cooling, screening, wrapping and other steps to produce the potassium calcium magnesium nitrate, potassium magnesium nitrate, zinc boron-rich potassium magnesium nitrate and zinc boron-rich potassium calcium magnesium nitrate granular fertilizer with the grain diameter of 1.5-4.0 mm.
Preferably, the boron-containing and zinc-containing auxiliary materials are boric acid, borax and zinc nitrate solids.
The invention has the beneficial effects that: compared with the prior art, firstly, the invention uses the middle-low grade phosphorite as the main raw material to prepare the potassium calcium magnesium nitrate and the potassium magnesium ammonium nitrate, effectively recycles the phosphorus, calcium and magnesium in the middle-low grade phosphorite under the condition of carrying out chemical mineral dressing on the middle-low grade phosphorite, has good economic benefit, does not generate tailings, effectively solves the problems of large land occupation, environmental pollution and the like caused by large accumulation of the tailings, and finally obtains the filter cake which can be used as the gypsum powder material for buildings without wasting resources; secondly, potassium sulfate is used as a decalcifying agent of the calcium magnesium nitrate concentrated solution, so that potassium ions and calcium ions in the calcium magnesium nitrate concentrated solution can effectively form coordination ions, and the finally obtained product contains more potassium ions; and finally, in the process of washing, the wastewater is recycled, so that the outward discharge of sewage and solid wastes is reduced, the production cost is saved, and the environment-friendly significance is achieved.
Drawings
FIG. 1 is a process flow diagram of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
The invention discloses a process for preparing potassium calcium magnesium nitrate and potassium magnesium ammonium nitrate from medium-low grade phosphate ore, which comprises the following steps: concentration: the quality fraction P is prepared by taking middle-low grade phosphorite as a raw material through the working procedures of crushing, calcining, digesting, leaching, filter pressing separation and the like2O5The low-magnesium phosphate concentrate with the weight percentage of more than or equal to 34.5 percent and the weight percentage of MgO less than or equal to 0.85 percent is collected and concentrated in the leaching solution in the filter pressing step, and the calcium magnesium nitrate concentrated solution with the weight percentage of more than 25 percent is obtained; decalcification: pumping the calcium magnesium nitrate concentrated solution into a decalcification reaction tank, reacting with a potassium sulfate solution from a dissolving tank, and filtering and separating to obtain a decalcification solution and a calcium sulfate filter cake; and (3) granulation: and (3) feeding the decalcification solution into a preheater and a heat exchanger, then treating by adopting a forced circulation type evaporator, separating the evaporated material by a flash separator, feeding the separated material into a granulation feeding tank, feeding the granulation feeding tank to a granulator for granulation, cooling and screening to obtain potassium magnesium nitrate and potassium calcium magnesium nitrate products. The method disclosed by the invention is used for mineral separation of medium-low grade phosphorite, the by-product decalcifying leaching solution of mineral separation can be used for producing urea calcium magnesium ammonium nitrate fertilizer or the by-product demagging leaching solution of mineral separation is used for producing ammonium magnesium nitrate and sulfate fertilizer, no tailings are produced, the mineral separation cost is saved, and the economic benefit and the environmental protection benefit are better; the obtained urea ammonium nitrate calcium magnesium fertilizer contains appropriate amount of acyl nitrogen, ammonium nitrogen, nitrate nitrogen, water-soluble calcium and magnesium, is fully water-soluble, has quick fertilizer effect, can be used as additional fertilizer, base fertilizer and the like, and is beneficial to crop growth and supplement of calcium and magnesium elements; the obtained ammonium sulfate nitrate magnesium fertilizer can be directly sold, can also be used as a raw material of a fertilizer product, an additive of the fertilizer product and an additive of a chemical product, and has wide application; and potassium sulfate is used as decalcifying agent to react with calcium in the concentrated calcium magnesium nitrate solution as the by-product of the chemical beneficiation of middle and low grade phosphate rock to obtain slightly soluble calcium sulfate, which is separated to obtain calcium sulfate for buildingThe gypsum powder material does not generate any waste, and can generate economic benefit; and the filtrate obtained in the production process can be recycled.
In some embodiments of the invention, the medium-low grade phosphate ore comprises the following components by mass: p2O524.34％、CaO 41.03％、MgO 4.79％、Fe2O30.34％、Al2O30.41％、F 3.16％、SiO23.38 percent, 4.50 percent of acid insoluble substances and 0.46 percent of organic matters.
In order to realize the scheme, in the concentration step, crushing the medium-low grade phosphorite to the particle size not more than 4.5 mm; the calcining temperature is controlled at 900-1100 ℃, and the time is controlled at 1.5-4 h; the leaching temperature is 75-90 ℃, the reaction time is 1.5-5h, and the reaction pH is controlled between 4.0-6.5. In the embodiment, the subsequent calcining process is favorably carried out, so that the middle-low grade phosphorite is sufficiently calcined, the decomposition of organic matters, impurities dolomite and calcite in the middle-low grade phosphorite is more favorably carried out, and if the particle size of the phosphorite is too large, the phosphorite cannot be burnt completely, so that the leaching and magnesium removal rate is low; calcining at the temperature of 900 plus 1100 ℃ can ensure that the decomposition rate of dolomite and calcite in phosphorite reaches 97-98.5%, decomposing to obtain magnesium oxide, calcium oxide and other substances, overburning the phosphorite if the calcining temperature is too high, not easy to extract, and not decomposing calcite and dolomite if the calcining temperature is too low, and after calcining, carrying out wet ball milling on the calcined ore to obtain phosphorite slurry, pumping the phosphorite slurry to a leaching reaction tank, adding ammonium nitrate and nitric acid for reaction, carrying out filter pressing separation, and washing for the second time, thereby obtaining the phosphate concentrate.
Decalcifying with potassium sulfate solution; the reaction temperature of the decalcification is controlled to be 20-110 ℃, and the reaction time is 3-6 h. In this example, calcium oxide, magnesium oxide, etc. are converted into calcium hydroxide and magnesium hydroxide after calcination; the added ammonium nitrate and nitric acid react with the substances to produce calcium nitrate and magnesium nitrate, potassium sulfate is added to react with the calcium nitrate to generate slightly soluble calcium sulfate, and the calcium sulfate can be effectively separated from the solution through the solubility at different temperatures, wherein the temperature is preferably controlled at 30-60 ℃, and the optimal temperature is 45 ℃; the decalcification solution is neutralized by one of calcium hydroxide and ammonia water, and the reaction pH is 6.5-7.0.
More specifically, the slurry after decalcification is subjected to first solid-liquid separation to obtain decalcification liquid and a filter cake, and the filter cake is washed and dried to obtain a calcium sulfate product for buildings; washing the filter cake for the first time, separating to obtain a first filter cake and a first filtrate, and collecting the obtained first filtrate to dissolve potassium sulfate placed in the dissolving tank; and adding water into the first filter cake for secondary washing, and then separating to obtain a second filtrate and a second filter cake, wherein the second filtrate is used as a first washing liquid of the next batch of filter cakes, and the second filter cake is dried and then used as a calcium sulfate product for buildings. In the embodiment, the filtrate generated in the whole decalcification process can be repeatedly recycled, so that the production cost is effectively reduced, and the emission of pollutants is reduced.
Pumping the decalcification liquid into a preheater, adopting condensate generated by medium-pressure steam as a heating medium, feeding the preheated decalcification liquid into a heat exchanger, then feeding the preheated decalcification liquid into a forced circulation type evaporator, controlling the temperature at 160-180 ℃, separating evaporated materials by a flash separator to obtain concentrated liquid, feeding the concentrated liquid into a granulation feeding tank, and feeding the concentrated liquid into a granulator for granulation to obtain potassium magnesium nitrate and potassium calcium magnesium nitrate products. In this embodiment, preheating is performed first to prevent the produced potassium magnesium nitrate complex ions and the like from being damaged due to rapid temperature rise; transferring the mixture into a forced circulation type evaporator for evaporation after the temperature rises to 150 ℃, then obtaining concentrated solution through a flash separator, and obtaining potassium magnesium nitrate and potassium calcium magnesium nitrate products by adopting at least one of high tower granulation, drum fluidized bed granulation, disc granulation, slurry spraying granulation and steel belt granulation; and subsequent materials are balanced in temperature by using a heat exchanger, and the evaporated decalcifying liquid is used as a heating medium, so that the steam consumption is effectively reduced, and the production cost is reduced.
If the fertilizer rich in zinc and boron is to be produced, the concentrated solution is subjected to heat exchange with the feed liquid to be evaporated through a heat exchanger and then is sent to a melting tank, auxiliary materials such as boron, zinc and the like are metered and then sent to the melting tank, and after the temperature is reduced to 130-150 ℃, the mixture is sent to a granulator for granulation, so that a zinc-boron-rich potassium magnesium nitrate fertilizer/zinc-boron-rich potassium calcium magnesium nitrate fertilizer product is obtained; the boron and zinc-containing auxiliary materials are boric acid, borax and zinc nitrate solid; the pH of the solution was adjusted with calcium hydroxide and ammonia water to 6.5-7.5. In this embodiment, since the fertilizer is used, it is necessary to control the acidity or alkalinity of the fertilizer to be near neutrality, so that the fertilizer can be effectively adapted to various plants; however, according to the prior art research, the precipitation of calcium sulfate is obtained under the alkaline condition, and the decalcified liquid mainly contains more acidic substances, so the pH of the solution is particularly adjusted by using the alkaline substances such as calcium hydroxide, free acid is converted into calcium sulfate and other precipitates under the pH condition to enter a filter cake, and the filtered decalcified liquid is concentrated and granulated to produce potassium calcium magnesium nitrate and potassium magnesium ammonium nitrate.
The first embodiment is as follows:
calcining 338kg of medium and low grade phosphorite at 900 ℃ for 4h to obtain 300kg of calcined ore, grinding to 1.0mm, adding 100kg of water for digestion, adding 400kg of ammonium nitrate with the concentration of 30% for leaching for 1h, adding 70kg of nitric acid with the concentration of 30% for adjusting the pH of slurry, leaching for 60 min at the temperature of 80 ℃, filtering, collecting filtrate, and simultaneously detecting the content of the washed filter residue to obtain a filter cake, namely phosphate concentrate with the mass percentage content of P2O534.54 percent of calcium magnesium nitrate and MgO0.82 percent of magnesium sulfate, concentrating the filtrate, removing excessive water to obtain 470kg of calcium magnesium nitrate concentrated solution with the mass fraction of more than 25 percent, adding 102kg of potassium sulfate into 170kg of water to prepare solution, adding the solution into a decalcification reaction tank for reaction, adding calcium hydroxide to adjust the pH of the solution to about 6.5 to obtain 586kg of decalcification solution and 127kg of filter cake with the main component of calcium sulfate, cleaning the filter cake for multiple times and using the filter cake as gypsum for building, wherein the gypsum contains CaO 39.09 percent by mass and H212.36 percent of O; transferring the decalcification solution into a preheater, preheating to 110 ℃ by using condensate generated by medium-pressure steam as a heating medium, transferring the decalcification solution into a heat exchanger, then feeding into a forced circulation type evaporator, controlling the temperature to be 160 ℃, and separating evaporated materials by a flash separator to obtain a concentrated solution with the concentration of 98%; then cooling to control the temperature to be 135 ℃, then feeding the mixture into a granulation feeding groove, and feeding the mixture to a granulator for granulation to obtain the magnesium potassium nitrateAnd potassium nitrate calcium magnesium product, potassium nitrate calcium magnesium is the mixture of magnesium nitrate, potassium nitrate, calcium nitrate; the potassium magnesium ammonium nitrate is a mixture of ammonium nitrate, potassium nitrate, calcium nitrate and magnesium nitrate.
The obtained components were tested and the results are given in the following table:
| potassium (%) | Calcium (%) | Magnesium (%) | Nitrogen (%) | |
| Potassium calcium magnesium nitrate | 14.97 | 1.93 | 5.96 | 18.94 |
| Potassium magnesium ammonium nitrate | 15.62 | 0.62 | 6.04 | 19.05 |
Example 2:
calcining 338kg of middle-low grade phosphorite at 1000 ℃ for 4h to obtain 295kg of calcined ore, grinding to 1.0mm, adding 100kg of water for digestion, and then adding 400kg of 30% nitreAmmonium leaching for 1h, adding 70kg nitric acid with the concentration of 30% to adjust the pH of the slurry, leaching at the temperature of 80 ℃ for 60 minutes, filtering, collecting filtrate, and detecting the content of the washed filter residue to obtain a filter cake, namely phosphate concentrate with the mass percentage of P2O534.57 percent and MgO0.81 percent, concentrating the filtrate, removing excessive water to obtain 470kg of calcium magnesium nitrate concentrated solution with the mass fraction of more than 25 percent, adding 102kg of potassium sulfate into 160kg of water to prepare solution, simultaneously adding the solution into a decalcification reaction tank for reaction, simultaneously adding calcium hydroxide to adjust the pH value of the solution to be about 5.0 to obtain 587kg of decalcification solution and 120kg of filter cake with the main component of calcium sulfate, washing the filter cake for multiple times and using the filter cake as gypsum for construction, wherein the gypsum contains 39.12 percent of CaO and H by mass percentage212.36 percent of O; transferring the decalcification solution into a preheater, preheating to 110 ℃ by using condensate generated by medium-pressure steam as a heating medium, transferring the decalcification solution into a heat exchanger, then feeding into a forced circulation type evaporator, controlling the temperature to be 160 ℃, and separating evaporated materials by a flash separator to obtain a concentrated solution with the concentration of 98%; then cooling, controlling the temperature to be 135 ℃, then feeding the mixture into a granulation feeding groove, and conveying the mixture to a granulator for granulation to obtain potassium magnesium nitrate and potassium calcium magnesium nitrate products, wherein the potassium magnesium nitrate is a mixture of magnesium nitrate, potassium nitrate and calcium nitrate; the potassium magnesium ammonium nitrate is a mixture of ammonium nitrate, potassium nitrate, calcium nitrate and magnesium nitrate.
The obtained components were tested and the results are given in the following table:
| potassium (%) | Calcium (%) | Magnesium (%) | Nitrogen (%) | |
| Potassium calcium magnesium nitrate | 13.45 | 2.45 | 6.01 | 18.78 |
| Potassium magnesium ammonium nitrate | 15.69 | 0.51 | 6.12 | 19.11 |
Example 3:
calcining 338kg of medium and low grade phosphorite at 1000 ℃ for 4h to obtain 295kg of calcined ore, grinding to 1.0mm, adding 100kg of water for digestion, adding 400kg of ammonium nitrate with the concentration of 30% for leaching for 1h, adding 70kg of nitric acid with the concentration of 30% for adjusting the pH of slurry, leaching for 60 minutes at 80 ℃, filtering, collecting filtrate, and simultaneously detecting the content of the washed filter residue to obtain a filter cake, namely phosphate concentrate with the mass percentage content of P2O534.63 percent of MgO0.78 percent, concentrating the filtrate, removing excessive water to obtain 470kg of calcium magnesium nitrate concentrated solution with the mass fraction of more than 25 percent, adding 102kg of potassium sulfate into 150kg of water to prepare solution, adding the solution into a decalcification reaction tank for reaction, adding calcium hydroxide to adjust the pH of the solution to be about 5.7 at the same time to obtain 590kg of decalcification solution and 116kg of filter cake with the main component of calcium sulfate, cleaning the filter cake for multiple times and using the filter cake as gypsum for building, wherein the gypsum contains CaO 39.15 percent by mass and H212.38 percent of O; transferring the decalcification solution into a preheater, preheating to 130 deg.C with condensate generated by medium pressure steam as heating medium, transferring the decalcification solution into a heat exchanger, and introducing into a forced circulation evaporator at 165 deg.CSeparating the evaporated material by a flash separator to obtain a concentrated solution with the concentration of 98%; then cooling, controlling the temperature to be 140 ℃, then feeding the mixture into a granulation feeding groove, and conveying the mixture to a granulator for granulation to obtain potassium magnesium nitrate and potassium calcium magnesium nitrate products, wherein the potassium magnesium nitrate is a mixture of magnesium nitrate, potassium nitrate and calcium nitrate; the potassium magnesium ammonium nitrate is a mixture of ammonium nitrate, potassium nitrate, calcium nitrate and magnesium nitrate.
The obtained components were tested and the results are given in the following table:
| potassium (%) | Calcium (%) | Magnesium (%) | Nitrogen (%) | |
| Potassium calcium magnesium nitrate | 12.87 | 3.66 | 6.13 | 18.63 |
| Potassium magnesium ammonium nitrate | 15.83 | 1.42 | 6.19 | 19.23 |
Example 4:
calcining 338kg of medium and low grade phosphorite at 950 ℃ for 4h to obtain 300kg of calcined ore, grinding to 1.0mm, adding 100kg of water for digestion, adding 400kg of ammonium nitrate with the concentration of 30% for leaching for 1h, adding 70kg of nitric acid with the concentration of 30% for adjusting the pH of slurry, leaching for 60 min at 80 ℃, filtering, collecting filtrate, and simultaneously detecting the content of the washed filter residue to obtain a filter cake, namely phosphate concentrate with the mass percentage content of P2O534.62 percent of MgO0.79 percent, concentrating the filtrate, removing excessive water to obtain 470kg of calcium magnesium nitrate concentrated solution with the mass fraction of more than 25 percent, adding 102kg of potassium sulfate into 180kg of water to prepare solution, adding the solution into a decalcification reaction tank for reaction, adding calcium hydroxide to adjust the pH value of the solution to be about 4.3 at the same time to obtain 578kg of decalcification solution and 135kg of filter cake with calcium sulfate as the main component, cleaning the filter cake for multiple times and using the filter cake as gypsum for building, wherein the gypsum contains CaO 39.49 percent by mass and H213.32 percent of O; transferring the decalcified liquid into a preheater, preheating to 130 ℃ by using a condensate generated by medium-pressure steam as a heating medium, transferring the decalcified liquid into a heat exchanger, then entering a forced circulation type evaporator, controlling the temperature to be 165 ℃, and separating the evaporated material by a flash separator to obtain a concentrated solution with the concentration of 98%; then cooling, controlling the temperature to be 140 ℃, then feeding the mixture into a granulation feeding groove, and conveying the mixture to a granulator for granulation to obtain potassium magnesium nitrate and potassium calcium magnesium nitrate products, wherein the potassium magnesium nitrate is a mixture of magnesium nitrate, potassium sulfate, potassium nitrate and calcium nitrate; the potassium magnesium ammonium nitrate is a mixture of ammonium nitrate, potassium nitrate, calcium nitrate and magnesium nitrate.
The obtained components were tested and the results are given in the following table:
| potassium (%) | Calcium (%) | Magnesium (%) | Nitrogen (%) | |
| Potassium calcium magnesium nitrate | 15.68 | 0.76 | 6.08 | 19.26 |
| Potassium magnesium ammonium nitrate | 16.02 | 1.25 | 6.21 | 19.32 |
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. The process for preparing potassium calcium magnesium nitrate and potassium magnesium ammonium nitrate from medium-low grade phosphate ore is characterized by comprising the following steps:
concentration: the quality fraction P is prepared by taking middle-low grade phosphorite as a raw material through the working procedures of crushing, calcining, digesting, leaching, filter pressing separation and the like2O5A low-magnesium phosphate concentrate with a content of not less than 34.5% and MgO not more than 0.85%, andcollecting the leachate in the filter pressing step for concentration to obtain a calcium magnesium nitrate concentrated solution with the mass fraction of more than 25%;
decalcification: pumping the calcium magnesium nitrate concentrated solution into a decalcification reaction tank, reacting with a potassium sulfate solution from a dissolving tank, adding an alkaline substance for neutralization, and filtering and separating to obtain a decalcification solution and a calcium sulfate filter cake;
and (3) granulation: and (3) feeding the decalcification solution into a preheater and a heat exchanger, then treating by adopting a forced circulation type evaporator, separating the evaporated material by a flash separator, feeding the separated material into a granulation feeding tank, feeding the granulation feeding tank to a granulator for granulation, cooling, screening and wrapping to obtain potassium magnesium nitrate and potassium calcium magnesium nitrate products.
2. The process for preparing calcium magnesium potassium nitrate and potassium magnesium ammonium nitrate from the medium and low grade phosphorite according to claim 1, characterized in that in the concentration step, the crushing comprises crushing the medium and low grade phosphorite to a particle size of not more than 4.5 mm; the calcining temperature is controlled at 900-1100 ℃, and the time is controlled at 1.5-4 h; the leaching temperature is 75-90 ℃, the reaction time is 1.5-5h, and the reaction pH is controlled between 4.0-6.5.
3. The process for preparing calcium magnesium potassium nitrate and potassium magnesium ammonium nitrate from medium and low grade phosphate ore according to claim 1, wherein decalcification is carried out by using potassium sulfate solution; the reaction temperature of the decalcification is controlled to be 20-110 ℃, and the reaction time is 3-6 h; neutralizing with one of calcium hydroxide and ammonia water to obtain a reaction pH of 6.5-7.5.
4. The process for preparing calcium magnesium potassium nitrate and potassium magnesium ammonium nitrate from medium and low grade phosphate ore according to claim 1, which is characterized in that the decalcified slurry is subjected to first solid-liquid separation to obtain a decalcified liquid and a filter cake, and the filter cake is washed and dried to obtain a calcium sulfate product for construction.
5. The process for preparing calcium magnesium potassium nitrate and potassium magnesium ammonium nitrate from medium and low grade phosphate ore according to claim 4, wherein the filter cake is washed for the first time, a first filter cake and a first filtrate are obtained by separation, and the obtained first filtrate is collected and used for dissolving potassium sulfate placed in a dissolving tank; and adding water into the first filter cake for secondary washing, and then separating to obtain a second filtrate and a second filter cake, wherein the second filtrate is used as a first washing liquid of the next batch of filter cakes, and the second filter cake is dried and then used as a calcium sulfate product for buildings.
6. The process for preparing calcium magnesium potassium nitrate and potassium magnesium ammonium nitrate from medium-low grade phosphate ore according to claim 1, wherein the decalcified liquid is pumped into a preheater, condensate generated by medium-pressure steam is used as a heating medium, the preheated decalcified liquid enters a heat exchanger and then enters a forced circulation type evaporator, the temperature is controlled at 160-180 ℃, the evaporated material is separated by a flash separator to obtain a concentrated solution, the concentrated solution enters a granulation feeding tank and is sent to a granulator for granulation, and potassium magnesium nitrate and potassium calcium magnesium nitrate products are obtained.
7. The process for preparing calcium magnesium potassium nitrate and potassium magnesium ammonium nitrate from the medium-low grade phosphate ore as claimed in claim 6, wherein the temperature of the concentrated solution separated by the flash separator is controlled at 155 ℃ after heat exchange with the feed solution to be evaporated, and then the concentrated solution enters the granulation feeding tank; the condensate produced by the concentration system is used for the second washing water of the first filter cake.
8. The process for preparing potassium, calcium, magnesium nitrate and potassium, magnesium nitrate from the medium-low grade phosphate ore as claimed in claim 6, wherein the concentrated solution is subjected to heat exchange with the feed solution to be evaporated through a heat exchanger and then sent to a melting tank, auxiliary materials such as boron, zinc and the like are metered and then sent to the melting tank, and after the temperature is reduced to 130-150 ℃, the temperature is sent to a granulator for granulation, so as to obtain the zinc-rich boron potassium, magnesium nitrate fertilizer/zinc-rich boron potassium, calcium, magnesium nitrate fertilizer product.
9. The process for preparing calcium magnesium potassium nitrate and potassium magnesium ammonium nitrate from medium and low grade phosphate ores according to claim 7, wherein the granulation section is followed by cooling, screening, wrapping and other steps to produce potassium calcium magnesium nitrate, potassium magnesium ammonium nitrate, zinc boron-rich potassium magnesium nitrate and zinc boron-rich potassium calcium magnesium nitrate granular fertilizers with the particle size of 1.5-4.0 mm.
10. The process for preparing calcium magnesium potassium nitrate and potassium magnesium ammonium nitrate from medium-low grade phosphate ore according to claim 8, wherein the auxiliary materials containing boron and zinc are solid boric acid, borax and zinc nitrate.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114524684A (en) * | 2022-04-24 | 2022-05-24 | 太原理工大学 | Production process of nitrophosphate fertilizer by freezing method with adjustable nitrogen-phosphorus ratio |
| CN116040662A (en) * | 2022-01-09 | 2023-05-02 | 四川大学 | Comprehensive recycling method for magnesium removal liquid for enriching phosphorite by nitric acid method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102126740A (en) * | 2011-01-20 | 2011-07-20 | 山东金正大生态工程股份有限公司 | Method for producing byproduct gypsum of niter-sulfur-based compound fertilizer by decomposing phosphorite with nitric acid |
| CN104860280A (en) * | 2015-05-06 | 2015-08-26 | 贵州省化工研究院 | Method for processing phosphorite tailings and producing magnesium-containing calcium carbonate |
| CN105272441A (en) * | 2015-09-23 | 2016-01-27 | 四川泸天化股份有限公司 | Process for production of liquid compound fertilizer by combination of decomposition of phosphate ore by use of nitric acid and removal of calcium by use of potassium salt |
-
2021
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102126740A (en) * | 2011-01-20 | 2011-07-20 | 山东金正大生态工程股份有限公司 | Method for producing byproduct gypsum of niter-sulfur-based compound fertilizer by decomposing phosphorite with nitric acid |
| CN104860280A (en) * | 2015-05-06 | 2015-08-26 | 贵州省化工研究院 | Method for processing phosphorite tailings and producing magnesium-containing calcium carbonate |
| CN105272441A (en) * | 2015-09-23 | 2016-01-27 | 四川泸天化股份有限公司 | Process for production of liquid compound fertilizer by combination of decomposition of phosphate ore by use of nitric acid and removal of calcium by use of potassium salt |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116040662A (en) * | 2022-01-09 | 2023-05-02 | 四川大学 | Comprehensive recycling method for magnesium removal liquid for enriching phosphorite by nitric acid method |
| CN114524684A (en) * | 2022-04-24 | 2022-05-24 | 太原理工大学 | Production process of nitrophosphate fertilizer by freezing method with adjustable nitrogen-phosphorus ratio |
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